Explain the Entry of Information for the Sensory Register, STM, and LTM
Sensory Register- Pre- attentive, you don't pay attention to the information in the sensory register until you focus on it and it is moved to STM
STM- Continued attention, rehearsal
LTM- rehearsal, repetition
Explain the Format of Information for the Sensory Register, STM, and LTM
Sensory Register- Literal copy of input
STM- acoustic, phonemic (Baddley Experiment)
LTM- semantic (Baddley Experiment)
The Baddley Experiment regarding the modular approach to memory: Asked how memory is represented in the two memory systems.
They presented participants with 4 lists of words
Afterwards, asked participants to recall words either immediately (testing STM), or after a distracter task (testing LTM). Dissimilar words were better remembered that similar words in both cases. Concluded that in STM information is represented acoustically, and in the LTM information is represented semantically.
Explain the capacity of memory in the Sensory Register, STM, LTM
Sensory Register- very large capacity (sight, sound, touch, taste, etc. all at once)
STM- Small, 7+/-2 chunks (See George Miller and Sidney Smith)
LTM- No known limit
George Miller, came up with the famous magic number 7+/-2 chunks of information using the digit span task. Participants are presented auditory with a series of digits and asked to recall that series in the same order. People with "good" memory can recall around 9-10 digits, people with "bad" memory can recall around 5 digits. Speaks to the limits of STM.
Sidney Smith- (Miller's student) found a way to transform binary code into an octal code, so if you had presented him with a series of 30-40 digits (1s and 0s) he would have been able to repeat it because he used a coding strategy via chunking.
STM has a limited capacity of 7+/-2 chunks. In order to increase the memory capacity, people chunk information.
Explain the Information Loss for the Sensory Register, STM, and LTM
Sensory Register- rapid decay
STM- decay, PI Displacement (see Underwood)
LTM- loss of accessibility (see Tulving & Pearlstone's Cue Dependent Forgetting)
Underwood- Interference theory states that people forget not because memories are actually lost from storage, but because other information gets in the way (they get confused). Described proactive interference and retroactive interference.
Tulving & Pearlstone's Cue Dependent Forgetting-
presented participants with a long list of words that belonged to categories. Because they had a lot of words to remember, participants forgot some categories, but if cued by the experimenter, they were able to remember words from the studied category. The right cue is going to make you find the trace of that specific memory. They introduced the distinction between accessibility and availability. Info may be available in LTM, but one might have trouble accessing it.
Explain the Trace Duration for the Sensory Register, STM, and LTM
Sensory Register- 250-500ms (see Sperling's experiment with the tachistoscope)
STM- 10-15s (see Brown-Peterson Paradigm)
Sperling- used tachistoscopic exposures of 50ms. Presented participants with a 3X3 matrix of letter, which they had to recall after the 50ms exposure. In the total recall paradigm one had to report as many letters as possible (typically 3-4 letters). In the partial report paradigm a tone was sounded that indicated which line was meant to be read (typically 100% accurate). If tonal delay was between 250ms-1s recall dropped off to the level of total recall. He concluded that the trace duration in the Sensory Register is somewhere between 250-500ms
Brown-Peterson Paradigm- participants are given a series of chunks, then immediately carry out a distractor task (usually counting backwards by 3s from a high number), then task is terminated and they are asked to recall the original series. If the distractor task is longer than 10-15s the participants can no longer recall the stimulus material. Concluded that STM lasts for 10-15s.
Explain the Retrieval of the Sensory Register, STM, and LTM
Sensory Register- read out
STM- serial exhaustive search (see Sternberg)
LTM- organized search processes, guided by retrieval cues (see Tulving and Pearlstone)
Sternberg- tested reaction time. Presented participants with strings of letters (or numbers) for a couple of seconds. Then asked participants to say whether a target letter was part of the previously presented string (yes or no), and measured the reaction time of each response. Concluded that search in STM can be either parallel or serial exhaustive search. Serial search can be either self-terminating or exhaustive.
Tulving & Pearlstone's Cue Dependent Forgetting- presented participants with a long list of words that belonged to categories. Because they had a lot of words to remember, participants forgot some categories, but if cued by the experimenter, they were able to remember words from the studied category. The right cue is going to make you find the trace of that specific memory. They introduced the distinction between accessibility and availability. Info may be available in LTM, but one might have trouble accessing it.
Explain the Maintenance of STM and LTM
STM- maintenance is through rehearsal. (repeating a phone number to yourself over and over before you dial it)
LTM- maintenance is through organization (see Tulving's Part/Whole Paradigm)
Tulving's Part/Whole Paradigm- people asked to study a list of 16 words, after they've learned the words, he split the group in 2: Group 1 was given a list of 32 words composed of the original 16+16 new ones, Group 2 was given a list of 32 new words. Group 2 performed better because of subjective organization. When given something to remember one imposes one's own organization onto the to-be-remembered material. Organization helps mainly because it formulated the rules of access into memory.